Bitumen, also known as asphalt, is a petroleum derivatives product which has been widely used as construction material. Bitumen, including naturally occurring bitumen and refined bitumen obtained from fractional distillation of crude oil, is semi-solid and very sticky at room temperature. When bitumen is heated up to an elevated temperature, it appears in a liquid form.
Bitumen is transported from oil refineries to user site in a number of ways. One way of transporting it is by heated tankers. Nevertheless, transportation by heated tankers consumes significant amount of energy, thus making it costly. Beside that, transportation of bitumen by heated tankers is also considered hazardous.
Another way for transporting bitumen would be transportation of cold bitumen in metal drums. While considered safe, transportation of cold bitumen by metal drums leads to wastage of bitumen as stickiness of bitumen makes it very difficult to recover all bitumen from the metal drums upon usage. About 2-3% of the bitumen is left as residues in the metal drums. Additionally, after it has been used once in transporting bitumen, the metal drums cannot be recycled for another usage, thus disposal of the used metal drums, with bitumen residues stick to the drums, leads to an environmental issue.
Attempts have also been made to use materials such as polymers and paper bag for packing bitumen. US Patent Publication no. 2009/0000976 discloses a method to pack bitumen using polymer bag for easy storage, handling, and transportation. To prepare a bitumen package, a pre-fabricated empty polymer bag having opening at the top is held firmly in a metal mould. The metal mould is then placed in a coolant/water tank. Following that, bitumen in liquid form is poured into the polymer bag with the help of a funnel. After that, the polymer bag is sealed and the sealed bag is placed on pallet, ready for further storage and transportation.